Captain Peter Willcox was found guilty of not following requests by Russian Coast Guard officers to stop his vessel, according to the border guard department of Russia's Federal Security Service in northwestern Murmansk Oblast.

Willcox, a U.S. citizen, is currently in two-month pretrial detention in Murmansk along with 29 other Greenpeace activists.

The activists -- citizens of 18 countries -- were arrested and later charged with piracy after two of them tried to scale a Gazprom offshore drilling platform last month.

They could face up to 15 years in jail if found guilty.

Russia's Investigative Committee said on October 9 that the activists may face new charges, including illegal drugs possession.